Loading of Biosensors

Electrical Biochips – The comfortable Way of detecting Biomolecules

Eight channel head over biochip wafer

Eight channel head over biochip wafer

 

The department “Biotechnical Microsystems (BTMS)” of the Fraunhofer ISIT is one of the worldwide leading groups in the field of electrical biochip technology. The electrical biochips offer intrinsic advantages because of particle tolerance and mechanical robustness by the direct transduction of biochemical reactions into electrical current.

The use of gold electrode arrays combined with integrated reference and auxiliary electrodes along with sensitive, selective measurement techniques like “Redox-Cycling” enables powerful sensor systems. These arrays are useful for the detection of a variety of analytes within one sample simultaneously. User-friendly operability is realized by integrating the biochips into cartridges. In combination with micro-fluidic components and integrated electronics, these electrical microarrays represent the basis of rapid and cost-effective analysis systems. They can be used to identify and quantify DNA, RNA, proteins, whole cells as well as haptens.

 

Droplets on a biochip

Droplets on a biochip

The used array chips consist of 16 gold electrodes for immobilizing capture molecules and the final electrochemical read out. These positions are 350 µm in diameter and therefore the capture molecules have to be deposited position specific by a piezodriven nanodispensing device. In our case we use the nanospotter technology from GeSiM (Left image). The chips are spotted directly on a diced wafer with 316 biochips glued on a dicing frame. Each chip will be picture recognized by the nanoplotters head camera before dispensing. Then the chips are spotted individually by 4 or 8 nanotips with a dispensed amount of 10 nl on each chip position. Afterwards the head camera takes a picture of each freshly dispensed chip for quality control (Right image). Then the chips are incubated, blocked, dried and are ready for assembling.


FhG-ISIT

FhG-ISIT

 

With Courtesy of Dr. Eric Nebling, Fraunhofer Gesellschaft Germany (ISIT)
Fraunhoferstrasse 1, D-25524 Itzehohe

 


–     L. Blohm et. al.: “Rapid detection of different human anti-HCV immunoglobulins on electrical biochips”, Antibody Technology Journal, 2014:4 23–32

–      S. Kraus et. al.: “Quantitative measurement of human anti-HCV Core immunoglobulins on an electrical biochip platform”, Biosensors and Bioelectronics 26 (2011) 1895 – 1901